<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        .pg-head{
            height: 200px;
            background-color: blue;
            line-height: 200px;
        }
        .w{
            height: 40px;
            width: 980px;
            margin: 0 auto;
        }
        .w ul li {
            list-style-type: none;
            float: left;
            padding: 0 8px 0 8px;

        }
        .w ul li:hover{background-color: red}
        body{

            margin: 0;
        }
    </style>
</head>
<body>
    <div class="pg-head">
        <div class="w">
            <ul>
                <li>标签一</li>
                <li>标签二</li>
                <li>标签三</li>
                <li>标签四</li>
            </ul>
        </div>
    </div>
    <div class="pg-body"></div>
    <div class="pg-footer"></div>

</body>
</html>